Stapling machine



March 16, 1937. s CROSBY 2,073,958

STAPLING MACHINE Filed Dec. 10, 1932 3 Sheets-Sheet 1 INVENTORStephenfl. lmwy WM,M M A 1% ATTORNEYS March 16, 1937. s. A. CROSBYSTAPLING MACHINE Filed Dec. 10, 1932 3 Sheets-Sheet 2 I i I H Wm IIINVENTOR NQ QQ F 0 m N M Wm M N mm March 16, 1937. CRQSBY 2,073,958

STAPLING MACHINE Filed Dec. 10, 1932 5 Sheets-Sheet 3 Ill I u m IAYIIIIA'IIIIIIIZYIIIIII INVENTOR Stephen A. Urosby BY Patented Mar. 16,1937 UNITED STATES PATENT OFFICE 2,073,958 STAPLING MACHINE ApplicationDecember 10, 1932, Serial No. 646,570

33 Claims.

This invention relates to improvements in stapling machines forfastening together sheets of paper, or the like.

Among the objects of this invention are the provision of improvedmechanism in a stapling machine, including a. stapling arm constructedof parts which are readily assembled and disassembled, which may becheaply manufactured and which provide for a rigid construction.

Other objects consist in the provision of a stapling arm including adetachable housing for the follower spring, and provision for preventingthe spring from interfering with the feeding movement of the staples,and improved staple 15 supporting means for supporting and holding thestaple against the staple driving and setting plate, and improved meansfor stopping and aligning sheets of paper.

' The invention also includes an improved base 9 construction togetherwith improved devices for holding resilient feet connected to said base.

The invention also includes an improved anvil construction provided withclenching depressions or recesses for clenching the staple for either 25permanently or temporarily securing the sheets together, and means forshifting the anvil for this purpose.

Other objects will appear from the following description taken inconnection with the draw- 30 ings, in which Fig. 1 is a perspective viewof an improved stapling machine;

Fig. 2 is a bottom plan view of the base of the machine;

Fig. 3 is a front elevation of the machine;

Fig. 4 is a rear elevation of the machine;

Fig. 5 is a longitudinal vertical central section of the machine;

Fig. 6 is a side view of the head of the stapling arm with the casingshown in longitudinal vertical section;

Fig. '7 is a section on the line 1-1 of Fig. 5;

Fig. 8 is a section on the line 8-8 of Fig. 5;

Fig. 9 is a view similar to parts of Fig. 7 show- 45 ing ,a' modifiedconstruction;

Fig. 10 is a view showing the main elements, of the stapling armdisassembled;

Fig. 11 is a vertical section on an enlarged scale corresponding to theportion of Fig. 5 show- 50 ing the staple supporting arm;

Fig. 12 is a bottom perspective showing the means for shifting theanvil;

Fig. 13 is a perspective view of the staple follower;

55 Fig. 14 is a perspective view of the means for securing the resilientfeet or blocks to the base; Fig. 15- shows the form of a staple whenclenched to permanently, secure sheets of paper together; and

Fig. 16 shows the form the staple assumes when it is bent to hold thesheets of paper together temporarily.

In the drawings I have illustrated a preferred embodiment of theinvention which will be described in detail, but it is to be distinctlyunderstood that various changes may be made without departing from thespirit of the invention and that the embodiment selected forillustration has merely been chosen for the purpose of describing theprinciples of the invention. I The stapling machine includes a base A, apivoted stapling arm B, a vertically movable plunger or staple drivingand setting means C, a staple follower D, a housing E for the followerspring etc., and an anvil F.

The base A, shown in Figs. 1, 2, 3, 4, and 5, may be cast or formed inthe shape shown in these figures in which it includes a top plate I, aflange 2. depending from said top plate and which may be shaped as shownin these figures providing a recess in the bottom of the base in whichmay be located the rubber feet 3 and 4 conforming to the shape of theflange and the top plate and projecting slightly below the flange. Thelower surfaces of the rubber feet may be provided with crossed ribs andgrooves, as shown in Figs. 2 and 5, for the purpose of preventing thestapling machine from sliding on a table on which it may be supported.These feet are pref erably recessed to receive projections 5 onanchoring plates 6, Figs. 2, 5, and 14, which plates are provided withapertures to receive screw bolts such as l by means of which the platesare secured in position.

The anchoring plate 6 for the foot 3 is secured to a U-shaped pivotbearing plate 8 which may be riveted against the lower face of the topplate I of the base. The legs 9 of the plate 8 project through slots inthe top plate I of the base and are provided with aligned pivotperforations described later. The anchoring plate 5 for securing thefoot 4 in position is secured to the bottom face of an anvilseat IIIwhich, as indicated in Fig. 5, is formed by depressing a portion of thetop plate I to form a seat for the shiftable anvil F.

The anvil F comprises an upper member or anvil proper ll, Figs. 1, 3, 5,and 12, which is provided with a single recess l2for clenching thestaples into the permanent form P shown in Fig.

15, and with a pair of spaced recesses l3 for clenching the staple intothe temporary form T shown in Fig. 16. The anvil F also includesdownward extending lugs or cars I4, Figs. 2, 5, and 12, which extendthrough elongated slots in the depressed anvil seat ill, the slots beingof greater length than the width of the ears, as indicated in Fig. 2,the ends of the slot forming limiting stops for the anvil in either ofthe two positions which it may assume. The ears l4 are provided withinverted T-shaped apertures for receiving a manipulative rod l5 and aplate spring l5 normally tending to hold the rod in its uppermostposition. The rod may be provided with grooves cooperating with arcuateslots IT in the side flanges of the base which hold the rod in positionand permit adjustment of the rod from one end of the slots to the otherfor moving the anvil .from one of its positions of adjustment to theother. The rod is also preferably provided with a groove at its centercooperating with a raised portion on the spring l6 for holding thespring in position in the anvil. The ends of the rod constitutemanipulative means, as shown.

The top plate I of the base A is also preferably provided with a slot20, Figs. 1, 2, 5, and 8, for receiving a stop and aligning means 2| forstopping and aligning the sheets to be stapled. This aligning means isadjustable within the slot 20 and is held in its adjusted position byits spring tension. The stop is provided with upwardly extending fingerpieces 22 by means of which the-stop may be compressed, as shown in Fig.8, prior to adjustment from one position to another.

The stapling arm B, as shown in Fig. 10, comprises a central main bodymember 25 which is provided with a narrow raised portion on which issecured a channelmember or rail 24 of a width equal to the channel inthe staples, and which is received by the staples as the staples areinserted in the arm. The forward end of the member 25 is provided withcheek plates 26 to which the front staple guide plate 21 may be securedby screws, as shown in Fig. 7.

The forward end of the member 25 is also provided with a cylindricalcavity 28 to receive a spring-pressed plunger 29 which operates a staplesupporting arm 30 pivoted at the point 3i to the wallsof a slot 32intersecting said cylindrical cavity and in which the arm 30 operates.

The rear guide plate 33, Fig. 10, is provided with a slot 34 coincidingwith the slot 32, the upper end of which constitutes means for limitingthe upper movement of the arm 30. The rear guide plate 33 is alsoprovided with a U-shaped slot 31, Figs. 10 and 11, through which thestaples are fed from the channel member or rail 24. The plate 33 issecured to the forward end of the arm 25, preferably by screws, so thatit may be readily assembled and disassembled. The front plate 21 ispreferably shaped as shown in Figs. 5 and 11 providing a slot 35 inwhich the extreme free end of the arm 30 operates.

The construction of the forward end of the spring-pressed plunger 29 andthe cooperating portion of the arm 30 is such that the spring pressureon the arm is substantially constant throughout its travel, so that thestaple will be held with substantially constant pressure against thedriving or setting plate 36 carried by the plunger C.

The staple arm B also includes side plates 40 and 4|, Fig. 10, which areprovided with overhanging flanges 42 and 43 to retain the staples inposition on the member 24. These side members are secured to the member25 by the pivot bolt 45, Figs. 1 and 5, and by screw bolts 46, 41 and48.

The flanges 42 and 43 of the members 40 and 4| at their forward ends areprovided with vertically extending frame plates or wings 49 and 50 whichare provided with slots 5i and 52 for receiving ears 53 and 54 on aplate 55 which in the assembled position rests on shoulders 56 on thecheeks 26 in spaced relation to the upper face of the rail 24, asindicated more clearly in Fig. 11, providing a passageway for thestaples between the plate 55 and the rail 24. The forward end of theplate 55 extends into the horizontal portion of the U-shaped slot 31 inthe rear guide plate 33. The plate 55 carries the spring supporting stud51 which positions the plunger operating spring 58 which bears againstthe inner face of the head 59 of the plunger.

The side members 49 and 50 are provided with outwardly or laterallyextending flanges 60 and BI, and 62 and 63, as shown in Fig. 10. Theseflanges, as shown in Figs. 5, 6, and 7, constitute guiding means for therectangular plunger 0. The side members 49 and 50 are provided withaligned holes 64 and 65 in which is supported the bolt or arbor 66 whichsupports the follower spring 61. The spring may be tensloned by rotatingthe bolt and for the purpose of locking the bolt in position the boltmay be provided with a head 68, as shown in Fig. 7, which may be locked.in position by means of a screw bolt 69 which is threaded into themember 50, as shown at 10,

and which is accessible through an opening in the housing E. If desired,the head of the adjusting bolt 66 may be tapered, as shown in Fig. 9,and the locking screw 69a may be provided with a tapered surface, thefunction of this tapered or wedge-shaped surface being to cam the springbolt 66 to the right, Fig. 9, and create friction between the body ofthe bolt and the walls of the holes 64 and 65 in the side plates 49 and50, thus securely holding the spring in adjusted position. One end ofthe bolt may be slotted, as indicated in Figs. 1, 5, 6, and 9, in whichone end of the spring 61 may be anchored and which may be engaged by ascrew driver inserted through a hole in the casing E.

The free end of the spring 61 is connected by means of an anchor bolt toa finger piece H which may be constructed as shown in Figs. 1 and 5, andwhich may be provided with a slot for freely and detachably receiving anupwardly and rearwardly projecting portion 12 on a plate 13 riveted tothe follower D, as shown in Figs. 5 and 13.

The side members 49 and 50, Fig. 10, are also provided with slots 14 and15 for receiving projections on one leg of a U-shaped spacing andlooking member 16, Figs. 5 and '7. The plunger C, as shown in Fig. 5, isprovided with a slot 11 in which operates a bolt 18 which limits themovement of the plunger under the operation of the spring 58. For thepurpose of retaining the bolt 18 in position the U-shaped locking plate16 may be compressed or otherwise placed under tension as the bolt isthreaded into it in position to control the operation of the plunger.

The spring 61 and the various parts of the head are preferably encasedin the casing E which comprises two members, 19 and 80. The member I9comprises a front wall and side walls and is secured in position by thebolts 41 and 48,

heretofore referred to. The rear member 80 C, and by means of whichmovement in an upward direction is communicated from the plunger C tothe driving or setting plate 36. The upper end of the driving plate isprovided with a tongue 83 which extends into the inner member of the cap59 and provides lateral shoulders in contact with the inner face of themember 84 for driving the driving plate 36 directly from the cap. Theupper end of the plunger C is also preferably provided with tongues 86which extend into said member 84 and which may be secured therein by anysuitable means. The shoulders defined by said tongue abut the inner faceof the member 84. The lower end of the driving and setting plate 36 isprovided with a slot 85 for receiving the end of the staple supportingarm 30 as the staple is being clenched, as shown in Fig. 11, to preventbinding.

Thearm B is held in the position shown in Fig. 5 by means of a spring 90which is received in an aperture in the top plate I of the base A and isseated at one end on the plate 8 secured ment or interlocking with themarginal portion or edge of the elongated slot in the plate 8 of thebase. The elongated slot in the plate 8 provides for clockwise movementof the arm 9| to disengage the hook 92 from the plate 8 to release thearm B for greater movement for purposes of providing access to variousparts of the arm, and also for the purpose of stapling a larger numberof sheets of paper or the like, that is, when latch 9| is released fromthe base, spring pivotally moves arm B upwardly and away from the base,thus increasing the gap at the forward part of the machine between thearm and base. The movable latch 9| as illustrated in Fig. 5 has a lowercurved terminal which for purposes of specification may be considered asa cam portion and the shoulder 92 above the cam portion may beconsidered as laterally extending from the body of the latch. It shouldbe appreciated that although block 8 is fastened to the base it may beconsidered as a part of the base I and constitutes a stop adapted toremovably interlock with laterally extending shoulder 92. The latchreceiving opening in stop 8 may be considered as a part of the enlargedopening in the base above it. This enlarged opening receives the lowerconvolution of spring 90 and the upper part of the block is an abutmentfor the lower convolution of the spring. For the purposes of compellinga complete downward and upward stroke of the plunger C, the plunger ispreferably provided with a full stroke rack 93 with which cooperates areversible pawl 94, spring-controlled as by spring 95, anchored as at 86to the frame plate 49, as indicated in Fig. 6.

As stated before, the anvil F is provided with a single clenching recess|2 which, when the anvil is in the position shown in Fig. 5, is alignedwith the staple driving and setting plate 36 which, upon operation ofthe machine, will cause the staple to assume the form shown in Fig. 15in which the sheets of paper are permanently secured together- The anvilis provided with a pair of clenching recesses II which may be alignedwith the staple driving and setting plate It by shifting the platerearwardly of the machine; that is, to the left, as indicated in Figs. 1and 5. When the machine is then. operated the staple will be bent intothe form shown in Fig. 16, in which the sheets of paper are temporarilysecured together, the staple being readily removable by lengthwisemovement in one direction to disengage one end thereof, and thenlengthwise movement in the opposite direction to disengage the otherend, or by a single continuous length- -'wise movement of the stapleuntil the staple is entirely disengaged from the sheets.

By locating the clenching depressions in different transverse lines onthe anvil the anvil may be shifted lengthwise of the machine so that theanvil in either of itspositions will lie entirely within the confines ofthe base of the machine. This also permits forming the seat for theanvil by merely depressing the top plate of the base of the machine, andalso permits the side flanges of the base of the machine to be slottedto permit adjustment of the anvil and to cooperate with the manipulativemeans carried by the anvil for holding the anvil in either of itsadjusted positions and for securely aligning the clenching recesses inthe anvil in alignment with the driving and setting plate 36.

By constructing the base as shown, the base may either be cast or formedof sheet metal. The operating arm B may readily be assembled by means ofseveral cross bolts which pivotally secure the arm to the base, andwhich secure the side guidemembers 4|! and 4| to the main body member25, and also secure the member 19 of the casing in position. As theguide members 40 and 4| are secured in position, the plate 55, whichconstitutes a seat for the spring 58, the spring retaining bolt 66 andthe U-shaped washer plate 16 are thereby secured in position. Theupright flanges 49 and 50 on the side members 40 and 4| also providemeans for guiding the plunger C which is also guided by the member 19 ofthe housing E which is secured in position by the same bolts 41 and 48which secure the side members 40 and 4| in position. By constructing theoperating arm B of the parts described, the central body member 25 maybe, if desired, die cast; the side members 40 and 4| may be made ofpressed and stamped material; the guide rail 2% may be made of pressedsheet material and preferably extends forwardly into engagement with therear guide plate 33 which is made of steel and which; together with thefront guide plate 21, is removably secured to the forward end of themain body member 25, whereby these parts which receive wear may bereadily replaced.

The staple driving and setting plate 36 is provided at its upper endwith a tongue defining lateral shoulders which abut against the innerface of the cap 59 so that the force is directly communicated from thecap to the end of the driving plate. The rivet 82 is employed forthepurpose of causing the driving plate to move upwardly with the plunger.This rivet engages an elongated hole, as shown in Fig. 5, to prevent therivet from operating to transmit the driving force from the plunger tothe driving and setting plate 35. The lower end of the plate is slotted,as shown in Figs. 10 and 11, in order that the end of the staplesupporting arm 30 may rest against the end of this slot when the plate36 is in its lowermost position, as shown in Fig. 11, after the staplehas cleared the end of the arm 30. This prevents any binding and lockingaction between the end of the arm 30 and the plate 36, such as wouldoccur if the slot were not provided. The rear end of the arm 30 ispreferably shaped so that the pressure of the spring tending to restorethe arm is substantially constant throughout the length of the travel ofthe arm.

The construction provides means for securely holding the spring seat 55in place and the rearward extension on the seat provides a means forpreventing the convolute spring 61 from interfering with the operationof the staple follower, as this spring is substantially fully expandednear the end of the forward movement of the follower.

The U-shaped locking plate 16 provides a means for locking the plungerlimiting bolt 18 in position which holds the rear casing member 8|] inassembled position on the arm B and. on the front member 19 of thecasing.

By means of the construction shown in Fig. '7, the spring supporting andtensioning bolt 66 may be locked in position after a proper adjustmenthas been effected in the tension of the spring.

The construction shown in Fig. 9 has the additional advantage ofcreating friction between the side of the bolt 66 and the walls of theapertures in the members 49 and 50.

The construction of means for limiting the upward movement of theoperating arm and of the seats for the spring effecting such movementinsures that the hook 92 of the arm is always in functioning positionunder the influence of the spring 90, but permits the hook to be readilywithdrawn to permit the operating arm to be raised high enough toaccommodate a large number of sheets.

While the invention has been shown in connection with an embodimentconstructed in accordance with the principles of the invention, it is tobe understood that various changes may be made without departing fromthe principles of the invention, and it is to be understood that it isthe intention to cover all equivalent constructions in the claimsregardless of any descriptive language that may be imported from thespecification into the claims.

What I claim is:

1. In a stapling machine, the combination of a base, an operating armpivoted thereto, a driving plunger carried by said arm, a staple drivingand setting plate operated by said plunger, means for feeding staplesunder said plate, a staple supporting arm pivoted in said operating armand functioning to hold staples in contact with the end of said drivingplate, said driving plate being recessed at its lower end to form ashoulder with which the free end of said supporting arm engages as thedriving plate moves into its final position.

2. In a stapling machine, the combination of a base, an operating armpivoted thereto, a spring, a limiting hook pivoted to said operating armand having its hooked portion engaging said base to limit the upwardmovement of said arm, and a shoulder on said hook constituting a seatfor one end of the spring, the other end of which is seated against saidbase, the pressure of said spring on said shoulder operating to hold thehook in engagement with said base, said base being slotted to permit ofa pivotal movement of said hook to disengage same from said base.

3. In a stapling machine, the combination of a base, an operating armpivoted thereto, a driving plunger mounted in the head of said operatingarm, a spring bearing against said plunger, a seat on said ar for saidspring, a follower spring for feeding sta les to be driven by saidplunger, and an extension on said seat overlying said staples, saidextension being offset with respect to said seat in a direction towardsaid follower spring for preventing interference between said followerspring and said staples.

4. In a stapling machine, the combination of a base, an operating armpivoted thereto comprising a central body member over which staples arefed, separate side members including inwardly extenQag flanges forretaining staples on said body member and for guiding the same in theirmovement toward the front end of said body member, upwardly extendingframe members formed on said flanges, a staple driving plunger carriedby the forward end of said arm, laterally and outwardly extendingflanges on the front edges of said frame members for guiding the rearside of said plunger, a housing cooperating with said last mentionedflanges for enclosing and guiding said plunger, downwardly extendingflanges on said housing overlapping said side members, and means forsecuring said downwardly extending flanges on said housing, said sidemembers and said body member together.

5. In a stapling machine, an operating arm comprising a main bodymember, upwardly extending shoulders formed on the sides and the forwardend of said body member, separate side members secured to said bodymember including inwardly extending flanges for guiding staples on saidbody member and including also upwardly extending guiding surfaces forguiding the rear side of a staple driving plunger, and a housingcooperating with said guiding surfaces for guiding said driving plunger,said housing resting on said shoulders and being provided with portionsoverlapping said side members, and means for securing said overlappingportions, said side members and said body member together.

6. In a stapling machine, the combination of a base, an operating armpivoted on said base comprising a main body member provided with astaple rail, side members provided with flanges overlying said rail,upwardly extending frame members formed on the free edges of. saidflanges near the front ends thereof, laterally extending flanges on saidframe members constituting guiding means for a staple driving plunger,and a casing enclosing said frame members and comprising a portionconstituting guiding means for a staple driving plunger, and a stapledriving plunger guided by said guiding means.

7. In a stapling machine, the combination of a base, of an operating armpivoted on said base comprising a main body member provided with astaple rail, side members provided with flanges overlying said rail,upwardly extending framev members formed on the free edges of saidflanges near the front ends thereof, laterally extending flanges on saidframe members constituting guiding means for a staple driving plungerand a casing enclosing said frame members and comprising a portionconstituting guiding means for a staple driving plunger, a stapledriving plunger guided by said guiding means, a staple follower movableon said rail, a convolute follower spring located between said framemembers, a follower spring'supporting and tensioning bolt rotatable insaid frame members, one end of which is slotted and is accessiblethrough an opening in said casing, a head on the other end of said boltin contact with the outer face of the adjacent frame member, and alocking screw bolt mounted in said adjacent frame member and providedwith a head bearing on the head of said screw bolt and accessiblethrough an opening in the casing.

8. In a stapling machine, a base, an arm pivoted to said base and havingspaced upstanding frame members, a. transversely disposed bolt rotatablysustained by said members and having an overhanging portion adapted tobear against one of said frame members, settable means carried by saidlast mentioned frame member and out of axial alinement with saidoverhanging portion and adapted to frictionally cooperate therewith toprevent rotation of said bolt, said arm having means for guidingstaples, a follower slidably mounted on said arm, and a spring adaptedto be adjusted upon rotation of said bolt and connected to the latterand said follower.

9. In a. stapling machine, a base, an arm pivoted to said base andhaving spaced upstanding frame members, a transversely disposed boltrotatably sustained by said members and having an overhanging portionadapted to bear against one of said frame members, an adjustable setscrew out of axial alinement with said bolt and having a head adapted tofrictionally cooperate with said overhanging portion for clamping thelatter against its adjacent frame member to pre vent rotation of saidbolt, a staple follower slidably mounted in said arm, and a springadapted to be adjusted upon rotation of said bolt and connected to saidfollower and bolt.

10. In a stapling machine, an operating arm comprising a main bodymember, spaced cheek members on the forward end of said member extendinglaterally and forwardly beyond said main body member and integraltherewith, a rear staple guide plate located between said cheek membersand secured against the front end of said body member, and a frontstaple guide plate secured to the front faces of said cheek members anddefining with said rear staple guide plate a vertically disposedpassageway for slidably guiding a staple.

11. In a stapling machine, an operating arm comprising a main bodymember, spaced cheek members on the forward end of said member extendinglaterally and in part forwardly beyond said member and integraltherewith, a rear staple guide plate located between said cheek membersand secured against the front end of said body member, a front stapleguide plate secured to the front faces of said cheek members anddelining with said rear staple guide plate a vertical passageway toreceive a staple, and a guide rail on said body member, said rear guideplate being provided with an inverted U-shaped. passageway through whichstaples fed over said rail enter said vertical passageway between saidguide plates.

12. In a stapling machine, a staple driving plunger, a head on said pler, a staple driving and setting plate provided with a tongue entering arecess in said head and defining a shoulder ged by said head, and aloose connection between said plunger and setting plate for moving saidplate with the plunger as the plunger is restored to normal position,said connection between the setting plate and the head on the plungerand the plunger providing for readily mounting and dismounting thesetting plate and providing means of self-alignment of said settingplate.

13. In a stapling machine, a staple driving and setting plate, a staplerail over which staples are fed under said driving and setting plate, aspringpressed staple supporting arm pivotally supported in said staplerail with its free end projecting under said setting plate to holdstaples in contact with the end of the driving and setting plate, and ashallow recess in the lower end of the driving and setting plate forreceiving the end of said supporting arm as a staple is moved past saidend of the supporting arm during the final movement of the driving andsetting plate.

14. In a stapling machine, the combination of, a base having spacedlongitudinally disposed slots, a slidable anvil provided with severaltypes of staple clinching recesses and having spaced depending lugsprojecting downwardly through said slots, said base having spaced sideseach including a cam slot, a transversely disposed rod connected to saidlugs and having terminal manipulating portions extending through saidcam slots and overhanging said sides, and an arcuate spring carried bysaid lugs and cooperating with said rod for removably holding the latterat corresponding terminal portions of said cam slots.

15. In a stapling machine, the combination of, a base having spacedlongitudinally disposed slots, a slidable anvil mounted on said base andprovided with several types of staple clinching recesses, spaced lugsdepending from said anvil and projecting downwardly through said slotsand slidably guided by the latter, said base having spaced alined cammeans, a transversely disposed rod slidably displaceable longitudinallyof said base and having reduced portions cooperating with said cammeans, manipulating means extending laterally of said rod andoverhanging said sides, and a. spring carried by said lugs andcooperating with said rod for removably holding the latter atcorresponding terminal portions of said spaced alined cam means.

16. In a stapling machine, the combination of, a base having an openingand constituting a stop, a staple carrying arm pivoted to said base, adisplaceable latch projecting downwardly from said arm and having alower part adapted to extend within said opening and comprising alaterally extending shoulder adapted to be free of said stop and abovethe latter whereby said arm may be upwardly displaced relative to saidbase and adapted to removably project underneath and against said stopupon downward displacement of said arm relative to said base todisconnectably interlock with said stop, to prevent upward displacementof said arm relative to said base, and spring means for holding saidshoulder against said stop.

17. In a stapling machine, the combination of, a base having a pivotedarm, a latch pivoted to said arm and projecting downwardly through saidbase, said latch having a laterally extending shoulder adapted toremovably interlock with said base upon pivotal movement of said latchto prevent pivotal displacement of said arm in one direction, and aspring surrounding said latch cooperating therewith and said arm to holdthe latter elevated, said shoulder upon reverse pivotal movement oi.said latch adapted to be disconnected from said base whereby said springautomatically pivotally displaces said arm to increase the gap betweensaid arm and base.

18. In a stapling machine, the combination of, a base comprising a stop,a staple carrying arm pivoted to said base, a latch pivoted to said armand projecting downwardly through said base, said latch having alaterally extending shoulder adapted to be above said stop when said armis in a raised position and adapted when said arm is in a depressedposition to removably interlock with said stop to prevent upward pivotaldisplacement of said arm relative to said base, a spring surroundingsaid latch for holding said arm in a pivoted raised position relative tosaid base pursuant to interlocking of said shoulder and stop, saidspring pursuant to disengagement of said shoulder and stop cooperatingwith said base and arm to pivotally elevate the latter and increase thegap between said arm and base.

19. In a stapling machine, the combination of, a base having a pivotedarm, a latch pivoted to said arm and having a laterally extendingshoulder adapted to removably interlock with said base to prevent upwardpivotal movement of said arm relative to said base, and spring means forholding said latch in an interlocked relation with said base wherebysaid arm defines with said base a gap, said latch upon manualdisplacement thereof adapted to shift said shoulder out of interlockingrelation with said base, said spring means upon removal of saidinterlocked relation automatically cooperating with said base and arm toincrease the gap formed thereby.

20. In a stapling machine, means for supporting a rotatable arbor havinga slot, a coiled springhaving one end retained in said slot, the latterproviding means for receiving a tool to permit rotation of said arborand winding or unwinding of said spring, and clamping means out ofalinement with the axis of and cooperating with-said arbor to hold thelatter in a set position of adjustment.

21. In' a stapling machine, the combination of,

means for supporting a transversely disposed rotatable'arbor having aslot, a coiled spring having one end retained in said slot, the latterproviding means for receiving a 'tool to permit rotation oi. said arborto adjust the tension of said spring, and adjustable means out ofalinement with the axis of and adapted to frictionally cooperate withsaid arbor to hold the latter in a set position of adjustment.

22. In a stapling machine, the combination of, means forsupporting atransversely disposed rotatable arbor having a diametrically arrangedslot, a coiled spring about said arbor and having one end retained insaid slot, the latter providing means for receiving a tool to permitrotation of said arbor to adjust the pressure of said spring, and anadjustable set screw having a head adapted to frictionally engage saidarbor to hold the latter in a set position of adjustment.

23. In a stapling machine, the combination of, a pivoted arm havingupstanding spaced wings, a rotatable arbor carried by said wings andhaving a slot, a coiled spring about said arbor and having one endretained in said slot, the latter providing means for receiving a toolto permit rotation of said arbor to adjust the pressure of said spring,a housing secured to said arm and having sides spaced from said wings,and clamping means rotatably carried by one of said sides forcooperating with said arbor to retain the latter in a set position ofadjustment.

24. In a stapling machine, the combination of, a pivoted arm havingspaced upstanding wings, a rotatable arbor carried by said wings andhaving a diametrically disposed slot, a coiled spring about said arborand having one end retained in said slot, the latter providing means forreceiving a tool to permit rotation of said arbor to adjust the pressureof said spring, said arbor having a flange overhanging one 01' saidwings, a housing secured to said arm, and adjustable clamping meansrotatable relative to said housing for trictionally engaging said flangeto hold said arbor in a set position of adjustment.

25. In a stapling machine, the combination of, a base having a pivotedarm, a latch having an upper portion pivoted to said arm and a lowerportion adapted to project through an opening of said base, said lowerportion defining a shoulder adapted to be projected through said openingto removably engage the lower face of base adjacent said opening andprevent upward pivotal displacement of said arm relative to said base,and spring means to hold said shoulder against said base, said springmeans upon removal of said shoulder causing said arm to pivotally andupwardly displace relative to saidvbase to increase the gap between theforward part of said arm and base.

26. In a stapling machine, a base having an anvil and a longitudinallyand centrally disposed slot bounded by a peripheral depending flange, aresilient stop having a contracted portion adapted to frictionally andremovably engage spaced portions of said depending flange, said guidehaving oppositely extending transverse portions each including anupstanding manipulatable projection, said projections being movabletowards each other to release said contracted portion from said sides topermit displacement of said guide relative to said slot, the forwardportion ,of said guide serving as stop means to prevent rearwarddisplacement of a member mounted on said base.

27. In a stapling machine, the combination of, means for supporting atransversely disposed rotatable arbor-having a diametrically arrangedslot, a coiled spring about said arbor and having one end retained insaid slot, the latter providing means for receiving a tool to permitrota- .tion of said arbor to adjust the pressure of said spring, and anadjustable set screw out of axial alinement with said bolt and having ahead comprising cam means adapted to frictionally engage said arbor tohold the latter in a set position of adjustment.

28. In a stapling machine, the combination of, a base, a staple carryingarm, means for pivotally supporting said arm, driving means for ejectinga staple carried by said arm, latch means projecting downwardly fromsaid arm and having a laterally extending shoulder, said base havingmeans for removably receiving a lower terminal of said projecting meansand including stop means adapted to engage said shoulder to limit upwardpivotal displacement of said arm relative to said base, and spring meansfor holding said shoulder engaged with said stop means.

29. In a stapling machine, the combination of, a base, a staple carryingarm, means for pivotally supporting said arm relative to said base,driving means carried by said arm for ejecting a staple supported by thelatter, pivotally displaceable means projecting downwardly from said armand having a shoulder, said base having means for removably receiving alower terminal portion of said displaceable means and including stopmeans adapted to disengageably cooperate with said shoulder to limitupward pivotal displacement of said arm relative to said base, andspring means for holding said shoulder engaged with said stop means,said terminal portion adapted to be manually displaced to be free ofsaid shoulder preparatory to upward pivotal displacement of said armrelative to said base.

30. In a stapling machine, the combination of, a base having an opening,a staple carrying arm, means for pivotally supporting said arm relativeto said base, driving means carried by said arm for ejecting a staplesupported by the arm, and projecting means extending downwardly fromsaid arm and movably supported by the latter and comprising a terminalcam portion,

and an extended shoulder adapted to be removably disposed in saidopening, said base having means to actuate said cam portion and shiftsaid shoulder for disconnectably interlocking with said base to preventupward pivotal displacement of said arm relative to said base.

31. In a stapling machine, the combination of,

a base, a staple carrying arm, means for pivotally supporting said armrelative to said base, driving means carried by said arm for ejecting astaple supported by the latter, projecting means extending downwardlyfrom said arm and movably supported by the latter and comprising anextended shoulder, said base having stop means for disconnectablyinterlocking with said shoulder to prevent upward pivotal displacementof said arm relative to said base, and spring means for holding saidshoulder in removable interlocking engagement with said stop means.

32. In a stapling machine, the combination of,

der in engagement with said stop means, said shoulder adapted to bedisengaged from said stop means, said shoulder when disengaged from saidstop means permitting upward pivotal displacement of said arm relativeto said base. said shoulder upon downward pivotal displacement of saidarm relative to said base adapted to move underneath said stop means andbe removably retained thereagain'st by said spring means.

33. In a stapling machine, the combination of, a base constituting astop and having an opening, a staple carrying arm, means for pivotallysupporting said arm, driving means for ejecting a staple carried by saidarm, a latch movably carried by said arm and comprising an extendedshoulder and a cam portion adapted to be disposed in said opening, saidcam portion on downward pivotal displacement of said arm relative tosaid base adapted to abut a wall of said opening to be out ofinterlocking relation with said stop, said cam portion on furtherdownward pivotal displacement of said arm adapted to be free of saidwall whereby said shoulder is disposed below and against said stop toprevent upward pivotal displacement of said arm relative to said base,and spring means for holding said shoulder in removable engagement withsaid stop, said latch adapted to be displaced relative to said wall todisengage said shoulder from said stop to permit upward pivotaldisplacement of said arm relative to said base. I

STEPHEN A. CROSBY.

